From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 997AF3BE641; Tue, 21 Jul 2026 21:47:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784670445; cv=none; b=cu02qm8TkLpNEIZlvcZqa9d41I9JMH/nW3uQ2jWHe7YaBhKKWcKWyEZwMUmvMeBljIqtimp1W3CxzTsPj/eoIgdq4SQFiKGLcn6vo8HjG/7EGWPsW2YyUgrT3JlpRkYMCVsQQ4PEgt9wF3BoPHBtViasHThX6yjqyOB9KvN6KOk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784670445; c=relaxed/simple; bh=CIIfnAhbdRIQNpMmx996Jb4EQ9fyDJVhlb8qSr5mjU0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oefOUdH74yh9NiUFX+7rhWq+XvhoRnmC7DScl1y9Yc+uUz7eH5bcdGH4HUEd3IhAj+fEBLm30dvpGqV8oDdINTtJEqFuN5sapfQ3Mpn/oShWqlvE/GPhV3M6aIpfmZ+VaVAAGugaJyfQ1pgEtl4AKAklEbv3BJSbvyGY4VAUvHg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bgMmzGQC; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bgMmzGQC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0B3AB1F00A3D; Tue, 21 Jul 2026 21:47:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784670444; bh=XflKVaqYPD+LX4+IqEX9qex3Iy37cjGO8ZUAxFPaUrg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=bgMmzGQCEz0d/0hQtW2naIe1MEaWl2mob+oSv+UWoKHIXpk2I2Gry3Lw3AXCmiyPz YRJbAoUpakUsqRoXExFcosuQYoyVgEvjHod39l7IQk/zayjRdle17rCES/FpuwJzHJ 271whMdrkIAshCDLtJ4K6PGBev2s+ZshIZhdZUDs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Sven Eckelmann , Sasha Levin Subject: [PATCH 6.1 0891/1067] batman-adv: ensure minimal ethernet header on TX Date: Tue, 21 Jul 2026 17:24:52 +0200 Message-ID: <20260721152444.464507227@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 49df66b7993c80b80c7eb9a84ba5b3410c8296a0 upstream. As documented in commit 8bd67ebb50c0 ("net: bridge: xmit: make sure we have at least eth header len bytes"), it is possible by for a local user with eBPF TC hook access to attach a tc filter which truncates the packet and redirects to an batadv interface. But the code assumes that at least ETH_HLEN bytes are available and thus might read outside of the available buffer. The batadv_interface_tx() must therefore always check itself if enough data is available for the ethernet header and don't rely on min_header_len. Cc: stable@vger.kernel.org Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Reported-by: Sashiko [ move from mesh- to soft-interface.c ] Signed-off-by: Sven Eckelmann Signed-off-by: Sasha Levin --- net/batman-adv/soft-interface.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 40354da5c5b555..a8239902b4428c 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -208,6 +208,9 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; + if (!pskb_may_pull(skb, ETH_HLEN)) + goto dropped; + /* reset control block to avoid left overs from previous users */ memset(skb->cb, 0, sizeof(struct batadv_skb_cb)); -- 2.53.0